Tuesday, July 23, 2013

Indian Pipe

While hiking in the Catskills last Sunday I saw a distinctive planet called Indian pipe (Monotropa uniflora).  While it superficially looks like a fungus, it's actually a flowering plant which lacks chlorophyll (hence the white color).

So, with no chlorophyll, this plant can't photosynthesize.  Plants like this are called saprophytes and, like fungus, obtain their nutrients from decaying plant matter.  This explanation is overly-simplistic, however, and the true relationship is far more interesting.

Throughout the forest floor, threads of fungus, called hyphae, are interacting with tree roots in a symbiotic relationship called a mycorrhiza.  Fungi get sugars from the trees (via photosynthesis of the trees leaves) while the fungi help pass minerals to the tree which they can more efficiently harvest from the soil.  It's a mutually beneficial relationship.

The Indian pipe, on the other hand, exploits this relationship in a parasitic way.  It taps into that underground network of fungal hyphae and extracts both minerals and sugars from it (the sugars that originally came from trees).  It most-likely does this by exploiting the same chemical cues that the fungi and trees use in their symbiotic relationship.

Indian pipe belongs to the Ericaceae family of plants - the same family as cranberries, blueberries, azaleas, and rhododendron.  So why did Indian pipe lose its chlorophyll?  Well, at some point, ancestors of this plant figured out how to tap into that fungal food source.  This allowed the plant to give up the costly process of photosynthesis and grow on the densely shaded forest floor where there was less competition from green plants.

By the way, should you encounter Indian pipe in your wanderings in the wood, don't bother picking it - it quickly turns black.

Other names for Indian pipe include corpse plant and ghost plant.  It was one of poet Emily Dickinson's favorite flowers and strikingly graces the cover of a posthumous book of her poems.

The flowers on the book came from a painting given to her in 1882, a few years before her death, by her neighbor Mabel Loomis Todd. Dickinson responded in a thank-you letter:

"That without suspecting it you should send me the preferred flower of life, seems almost supernatural… I still cherish the clutch with which I bore it from the ground when a wondering child, and unearthly booty, and maturity only enhances the mystery, never decreases it.”

Some have compared Dickinson, the reclusive lady dressed in white, to the pale Indian pipe living alone on the melancholy shaded forest floor.
'Tis whiter than an Indian Pipe —
'Tis dimmer than a Lace —
No stature has it, like a Fog
When you approach the place —
Nor any voice imply it here
Or intimate it there
A spirit — how doth it accost —
What function hath the Air?
This limitless Hyperbole
Each one of us shall be —
'Tis Drama — if Hypothesis
It be not Tragedy —

1 comment:

  1. Excellent blog, we certainly share the same interests .... your students are very lucky.